diff --git a/bin/setup.sh b/bin/setup.sh
index f49dd48d..9111921f 100644
--- a/bin/setup.sh
+++ b/bin/setup.sh
@@ -22,7 +22,7 @@ if [ ! -f configure ]; then
 fi
 
 echo "Creating build directory ..."
-mkdir build
+mkdir -p build
 
 echo "Setup is complete.  To build libslax:"